Simplifying a Makefile

I have a makefile like the one below and I am trying to simplify it. I know I should be assigning variables to cut down on repeated things but I am still confused as to how to properly simplify this as small as possible.

```
#
# Linux makefile
# Use with make
#

.SUFFIXES:
.SUFFIXES: .o .asm .cpp .c

AS=nasm
ASFLAGS= -f elf
CFLAGS=
CC=gcc
CXX=g++
CXXFLAGS=

.asm.o:
$(AS) $(ASFLAGS) $*.asm

.cpp.o:
$(CXX) -c $(CXXFLAGS) $*.cpp

.c.o:
$(CC) -c $(CFLAGS) $*.c

all: prime math sub1 sub2 sub3 sub4 sub5 sub6 first memex dmaxt asm_io.o fprime quadt test_big_int

prime: driver.o prime.o asm_io.o
$(CC) $(CFLAGS) -oprime driver.o prime.o asm_io.o

math : driver.o math.o asm_io.o
$(CC) $(CFLAGS) -omath driver.o math.o asm_io.o

first : driver.o first.o asm_io.o
$(CC) $(CFLAGS) -ofirst driver.o first.o asm_io.o

sub1 : driver.o sub1.o asm_io.o
$(CC) $(CFLAGS) -osub1 driver.o sub1.o asm_io.o

sub2 : driver.o sub2.o asm_io.o
$(CC) $(CFLAGS) -osub2 driver.o sub2.o asm_io.o

sub3 : driver.o sub3.o asm_io.o
$(CC) $(CFLAGS) -osub3 driver.o sub3.o asm_io.o

sub4 : driver.o sub4.o main4.o asm_io.o
$(CC) $(CFLAGS) -osub4 driver.o sub4.o main4.o asm_io.o

sub5 : main5.o sub5.o asm_io.o
$(CC) $(CFLAGS) -osub5 main5.o sub5.o asm_io.o

sub6 : main6.o sub6.o
$(CC) $(CFLAGS) -osub6 main6.o sub6.o

asm_io.o : asm_io.asm
$(AS) $(ASFLAGS) -d ELF_TYPE asm_io.asm

array1 : driver.o array1.o array1c.o
$(CC) $(CFLAGS) -oarray1 array1.o array1c.o asm_io.o

memex : memex.o memory.o
$(CC) $(CFLAGS) -omemex memex.o memory.o

dmaxt : dmaxt.o dmax.o
$(CC) $(CFLAGS) -odmaxt dmaxt.o dmax.o

quadt : quadt.o quad.o
$(CC) $(CFLAGS) -oquadt quadt.o quad.o

readt : readt.o read.o
$(CC) $(CFLAGS) -oreadt readt.o read.o

fprime : fprime.o prime2.o
$(CC) $(CFLAGS) -ofprime fprime.o prime2.o

test_big_int : test_big_int.o big_int.o big_math.o
$(CXX) $(CXXFLAGS) -otest_big_int test_big_int.o big_int.o big_math.o

big_int.o : big_int.hp

If you are using GNU Make, you can simplify

prime: driver.o prime.o asm_io.o
    $(CC) $(CFLAGS) -oprime driver.o prime.o asm_io.o

to

prime: driver.o prime.o asm_io.o

and a generic target building rule

%: %.o
    $(CC) $(CFLAGS) -o $@ $?

Most of the other targets can be similarly simplified.

math : driver.o math.o asm_io.o

first : driver.o first.o asm_io.o

sub1 : driver.o sub1.o asm_io.o

The generic target building rule will take care of building the executables from the dependent .o files.

StackExchange Code Review Q#80042, answer score: 2